OBJECTIVES: To assess patient safety and to evaluate operator acceptance to the technology of neurally adjusted ventilatory assist. DESIGN: A within-patient crossover study. SETTING: A ten-bed tertiary care university hospital pediatric intensive care unit. PATIENTS: A total of 21 mechanically ventilated infants and children aged 2 days to 15 yrs suffering from a variety of disorders. The majority of patients were treated after cardiac surgery. INTERVENTIONS: In patients with pressure-support ventilation, a nasogastric neurally adjusted ventilatory assist catheter was positioned to detect the diaphragm electrical impulse. Initiation and termination of ventilatory support for each breath could then be regulated either through conventional volume or pressure changes or through changes in the detected diaphragm electrical impulse signal. Ventilation was started as pressure-support ventilation for 30 mins, changed to neurally adjusted ventilatory assist for 30 mins, switched back to pressure-support ventilation for 30 mins and then neurally adjusted ventilatory assist until an end-point criterion was reached. MEASUREMENTS AND MAIN RESULTS: There were no serious adverse events during the study and all patients were circulatory and respiratory stable. The neurally adjusted ventilatory assist catheter was easy to place. The treatment time with neurally adjusted ventilatory assist ranged from 1 to 8 hrs (median = 2.5 hrs). During neurally adjusted ventilatory assist, the peak airway pressures decreased as compared with pressure-support mode but the mean airway pressures were not significantly changed.The respiratory rates increased during neurally adjusted ventilatory assist. The neural trigger on was first in 68% (median) whereas the neural trigger off was first in 88% (median) as compared with the pneumatic trigger on and off. Eight of the patients could be extubated in close connection to the termination of the neurally adjusted ventilatory assist treatment. CONCLUSIONS: We feel that neurally adjusted ventilatory assist would be safe and potentially efficacious to ventilate infants and children. It has the potential for improved patient-ventilator synchrony, decreasing airway pressures, and it might lead to earlier extubation.